Wall scraper and well logging tool



March 21, 1944. w. 1.. CHURCH 2934415598 WALL SCRAPER AND WELL LOGGING TOOL -Fil ed Jan. 6, 1942 5 Sheets-Sheet 1 l4 l3 mam/(M F7 2). 3

March 21, 1&44. w. L. CHURCH- WALL SCRAPER AND WELL LOGGING TOOL Filed Jam 6, 1942 3 Sheets-Sheet 2 Mia f,

March 21, 1944.

w. 1 CHURCH WALL SCRAPER AND WELL LOGGING TOOL Filed Jan. 6, 1942 3 Sheets-Sheet 3 Patente d Mar. 21, 1944 UNITED STATES PATENT OFFICE 2.344.598 WALL scnsrsa AND wan. Looonva 'roor.

Walter L. Church, Houstom'lfex. Application January 0, 1942, Serial No. 425,126

8 Claims. (01. ass-1.4)

This invention relates to a tool for use in a well bore designed to take samples of the side wall formation and to bring the samples to the ground surface for inspection. 7

An object of the invention is to provide a tool of the character described that may be lowered into the well bore while in inactive position and then actuated to active position whereby a sample of the formation may be taken from the side walls of the bore to be withdrawn to the ground surface.

A further object of the invention is to provide a tool of the character described so designed that the material which may have been deposited on the walls of the bore bythe drilling fluid may be scraped off and removed so as' to expose the natural formation to the end that an electrical well logging apparatus may be used to test the natural wall Another object of the invention is to provide in combination an electrical well logging device formation as thus exand side wall sample taking device. At the present time, it is common practice torun a well logging tool on a wire line into the well so as to locate'diiferent formations and to thereafter run a side wall sample taking tool on a string of drill stem to obtain samples of the various formations thus located. This method is not entirely satisfactory as wire line measurements vary, to

I present time, the electrical instrument is'lowered into a well after the well has been drilled and wherein the walls of the well are covered with'deposits from the drilling fluid. These deposits come from different formations and differ widely in conductivity. They cover the natural formation and consequently it is difilcult if not impossible to obtain a true reading of the nat-' ural formations, so covered by an electrical well logging device. By the use of the apparatus herein described, the foreign deposits may be first removed from the wall of thewell and the natural formation exposed and a true potential gradient of the formation may be obtained by the use of the well logging apparatus forming a part of this invention.

The invention herein disclosed constitutes an improvement over that disclosed in Patent No. 1,998,075, issued to applicant on April 16, 1935, and in Patent No. 2,053,698, issued to applicant on September 8, 1936. Other objects will be apparent from the following specification as illustrated by the accompanying drawings, wheretion, showing the sample taking device in inactive position.

Figure 2 shows a similar view showing the sample taking device in active position.

Figure 3 shows a fragmentary, vertical sectional view showing the sample taking device in active position with the recovery device low-- ered into the drill stem.

Figure 4 shows a cross-sectional view taken on the line of Figure 1.

Flgure'fi shows a cross-sectional view taken on the line 8-6 of Figure 1.

Figure 6 shows a cross-sectional view taken on the line 8-8 of Figure 1.

Figure 7 shows a fragmentary, vertical, sectional view of the sample recovery apparatus in position to receive the sample from the sample taking device.

Figure 8 shows a side-elevational view of the recovery device shown partly in section.

Figure 9 shows a side elevation of the lower end of the tool showing also a wiring diagram,-

and

Figure 10 shows a side elevation of the drill stem showing the tool connected to the lower at the ground Referring more particularly to the drawings,

I the numeral l designates a tubular drill stem special coupling 2 which is slightly flared at itsto the lower end 'of' which there is connected a lower end-and to the lower end of which there is connected a housing 3 for the well logging device more particularly hereinafter described. At the lower end of this housing. there is a guide plug 4, said housing and plug forming alsoa spaced from the inner wall of the coupling.

This extensioh contains the sample receiving chamber 8 and on opposite sides has the rela- Figure 1 shows aside elevation, partly in secthere is a downwardlylacing rece against the inside wall of the coupling \2, as more v accurately shown in-Figure 6. The cylinder 5 is spaced from the coupling 2 and at opposite sides has the relatively wide vertical ribs l0, l0, which fit closely against the inside walls of said coupling as shown in Figure 5. The ribs 9 are staggeredwith respect to the ribs l and are thus provided through which drilling fluid may flow downwardly from the drill stem l into the lower end of the cylinder 5.

Within the cylinder 5, there is a plunger II of a general tubular i'orm whose upper end is formed solid, as shown in Figures 2 and and whose connecting upper and lower channels H and i2 lower end is open. The lower end of the plunger coil spring it which normally holds the plunger in its lowerposition as shown in Figure 1.

Around the lower flared end of the coupling 2, there is an annular expander H as shown in Figures 1, 2 and 5.

The cylinder 5 and the surrounding coupling 2 have the oppositely disposed vertical slots It, said slots on said opposite sides registering and said slots being cut through the ribs it of the cylinder 5 as shown in Figure 5. A pin it extends transversely through the solid end of the plunger I3, as shown in Figure 5, with its ends extended through the slots it on each side. This pin limits the movement 0! the plunger in each direction and its outer ends are fitted into bearings of the expander whereby the expander ing edges.

Each housing 2i is provided with a downwardly ss 23 wherein the corresponding probe 22 is fitted closely and the upper. end or each probe is pinned in the housing by the transverse pin 24. The lower ends of the probes, therefore,

may be swung outwardly into position shownin face 25 which. works incontact with the out-- wardly tapering-inside faces 25 of the probes, so that upon upward movement of the expander, the lower ends of the probes ,will .be forced outwardly.

The tool, as assembled in Figure 1, may be lowered into the well. The spring I! will hold the plunger II and the expander I! in their lowermost position while the tool is being lowered. Circulation may be maintained in the bore by the flow ofdrilling fiuid downwardly through the drill stem and out through the aligned passageways 21 and '28-. The passageways 21 lead outwardly through the ribs 8 and coupling 2 and the passageways 28 continue'on outward vly through the probes. When it is desired to take a sample of the wall .iormation or .to remove the wall coating, hereinabove referred endof the sample receiving chamber -8.. The

'gage the upper end of the sleeve.

, ass-aces tively wide vertical ribs 0, l, which fit closely drilling fluid will thereafter be forced under pressure through the passageways Ii and i2 and will enter the lower end of the cylinder 5 and will operate to move the plunger i3 upwardly into the position shown in Figure 3 and the expander I! will be carried upwardly with the plunger and will engage behind the probes 22 and will force them outwardly. The plug 29 may then be engaged by a grappling tool of conventional design,

tions of it will pass upwardly through the pass sageways 2t and 21, and will enter and fill the chamber 8. This chamber may be made of any desired capacity so as to receive a substantial.

sample.

It is to be understood that at this time the drill stem I as well as the well bore 3!, are filled with drilling fiuid so that the static pressure will be the same.

When a sufllciengsample has been collected in the chamber 8, a sample removing tool, such as shown in Figure 8, may then be lowered through the drill stem and will land on the upper end of the chamber '8- as illustrated in Figure 3.

This sample removing tool will now be described. It embodies a tubular barrel 32-having the upwardly opening valve 23 near itslorwer end and beneath it the downwardly opening ball valve 34 which is normally held against its seat 35 by a strong coil spring beneath it. Screwed onto the upper end of the barrel 32, there is a head 21 having an outlet passageway 38 extend-v ing upwardly therethrough and turned outwardly through the side of the head as shown in Figure 3. This passageway is normally closed by an upwardly opening valve 39 which is held against its seat 40 beneath by means of a strong coil spring 4| above. v

Fitted over the lower end of the barrel 82, there is a sleeve 42 which is held in its lower position, temporarily by means oi the frangible pins 43 which are carried by the-barrel and en- The lower end of this sleeve is tapered to land on the tapering seat .44 at the upper end of chamber 8 and also has an inlet passageway 45. When this tool lands on the seat it is empty and upon the application of pump"jpressure to the drilling fiuid above, the barrel will be forced further downwardly shearing the pins 43. The lower endv oi the barrel has a vertically elongated 'side slot 48 4 and a pin 41- is anchored to the sleeve 42 and exend oi. the pin 41 will engage theball valve 34 and force it over to one side of its seat 35. The tool should now be moved upwardly so that the free ends of the probes 22 will not beembedded in the wall formation and the pressure oi the fluid in the bore 3| willforce the contents of the chamber 8 up through the passageway 45 and on up past the valves 34, 33 and into the sample receiving chamber 48 above said last mentioned valve. The grappling tool, as 30, may now again be lowered and engaged with the head 31 as shown in Figure v3 and the sample removing tool removed from the drill stem with the sample therein and trapped between the valves 33, 39. when this tool is removed from the well, an un seating tool may be screwed through the tapped I assume hole 48 opposite the valve 8!. a This unseating tool is designated generally by the numeral 44 and its inner end has a reduced release finger II which will engage the valve 88. when the unseating tool is screwed into place, and unseat said valve from its seat 48 thus allowing the sample to escape through the channel or duct 84 for inspection. However, if desired, before unseating the valve 8!, a pressure gauge as 82 may be screwed into the laterally turned internally threaded end 88 of the passageway 88 and the valve 88 then unseated and the pressure of the sample contained in the chamber 88, thus ascertained before said sample ls released from said chamber. Any solid sample which may accumulate in the chamber 48 may be rendered is coupled through the transformer 18 into the voltage amplifier tube 11. I The numeral 18 designates the output transformer, one side of its secondary winding being connected through the conductor II to the-common amplifier ground I4 and'in turn through the connector 81 to elec- 'trode 4. The other side of the secondary windaccessible by unscrewing, the head 81 from the designated to receive the nut 58. Beneath the solid connection 8a the housing is formed of a cylindrical case I! which is covered on the outside and lined on the inside with the insulating coatings 84, I8.

Threaded into the upper end of the case 51 there is a ring 80, which is insulated from the connection 8a by the insulating material 8|. The stud 55 extends through the ring 88 and is maintained in assembled relation therewith by means of the nut 58 which is also insulated from the ring 88, as more clearly shown in Figure l. Screwed into the lower end of the case 61 there is a ring 42 formed of insulating material. The guide plug 4 is fitted against the lower end of the case 81v and insulated therefrom by the insulating material 88. ll stem 84 is fitted downwardly through the ring 82. and through the plug 4. This stem is formed with a head 88 which engages the inner end of the ring 42 and its lower end is externally threaded to receive a nut 80 which is countersunk into the lower end of the plug and which serves to clamp the plug to the lower end of the case 81. The stem 84 is not insulated from the plug 4 and they form an electrode to which the conductor 81 is connected.

Extended through the wall of the case 81 there -is an electrode 88 which is insulated from the case by the insulation-88. A conductor" is connected to the electrode 88.

A voltage generating and measuring circuit is illustrated diagrammatically in Figure 9 and housed within the case 81 and includes a vacuum tube voltage measuring circuit II which measures the voltage between the electrodes 4 generator 12 is determined by the voltage'drop.

across the resistor I8. Thus a voltage change across the electrodes 4 and 88 causes a voltage 7 change across the resistor 18. The transformer.

18 forms the tank circuit of signal generator 12. I

ing of transformer 18 is connected through the conductor 48 through the coupling 8a to the drill stem which forms the third electrode. The voltage produced by thesignal generating circuit is thus amplified by the tube 11 and fed into the drillstem and electrode 4. The out-put circuit is completed by the generated current passing through the bore hole side wall formation be-- tween the electrode 4 and the drill stem. A portion of this voltage is measured bythe vacuum tube measuring circuit H between the electrodes 4 and 84. The battery 8| supplies the filament voltage for the tube of circuit 1| and the tubes of generator 12 and amplifier I1 and thebattery 82 is the high voltage plate supply for the tubes of H, 12 and II. The condenser 88 is a direct current blocking condenser to the vacuum tube .ll. The signal to be received at the ground surface is carried up by means of the drill stem I. As shown by .Figure 10, a suitable frequency measuring device 84 is set up at the ground surface. the drill stem- I by means of an induction coil, or under certain conditions, it might be found most practical to use a direct connection to said drill stem. Said frequency measuring device 84 also includes an audio-frequency amplifier and a suitable means for measuring the frequency of the signal that is conducted to the surface by the drill stem.

When the device has been lowered into the well and the foreign deposits have been removed by the scrapers 22 to expose the natural forms-- tion. the drill stem is then elevated so as to bring the electrodes 4 and 84 opposite the natural stratum' thus exposed in order to measure the resistivity of said exposed stratum. The voltage out-put of vacuum tube I1 is constant over the entire audio-frequency range. Thus with a high resistivity between electrodes -4 and 48, there is a high voltage and low current indicated in the stratum. With a low resistivity of the stratum there'is developed a low voltage and a high current between the electrodes 4 and 68. A change of resistivity between electrodes 4 and 68 causes a change in voltage between these electrodes, this voltage being applied tothe grid of vacuum tube ll, thus causing a change in the cathode current of said vacuum tube II. The amount of current drawn by the cathode of vacuum tube ll determines the voltage drop across the resistor I8. Since the cathode of both voltage measuring circuit Ii and signal generator .1! are connected to a common side of resistor 18, anychange in cathode voltage of circuit II is also applied to the cathode of generator 12. The frequency generated by generator I2 is regulated by the voltage applied to its cathode. It can be seen that with a certain resistivity in the earth stratum a certain audio-frequency signal will be generated and produced by the amplifier. Thus. a given audio-frequency will indicate a given resistivity,-enabling the o'perator at the surface to record changes in resistivlties of the strata of the bore hole.

The invention includes not only the wall.

scraper and electrical logging device but also The signal generated by the generating circuit" The device 84 maybe loosely coupled to the method of the formation strata in a well, ascertaining the nature of the stratum a channel, means to move the probe to activeposition to engage the wall of the well bore, said probe being mounted relative to the inlet wheregage the wall of the well and toremove-a portion of the formation therefrom upon down- 1 ward movement of the device in the well, said outwardly movable member being shaped. to di rect the removed formation through said inlet into said chamber upon such movement or the deviceintheweil.

chamber therein provided with an inlet and adapted to be connected to a tubular operating string, an outwardly movable member on the by to cause the wall formation to pass along-said channel and through said inlet into the chamher, when the probe is inactive position, upon longitudinal movement of the device in a well.

2..A device for taking samples from a well comprising a sample receiving chamber having an inlet, a wall scraper mounted relativeto the body, means for actuating said member outwardly into position to engage the wall of the well bore and to remove a portion of the forma-.

tion therefrom upon downward movement'oi' the device in the well, means arranged to be actuated by fluid pressure exerted through said memchamber wall and movable to active or inactive positions, means arranged to be operated by fluid under pressure to move the scraper to active position to engage the wall of the well bore, said scraper being shaped to direct wall formation through said inlet into the chamber, whenthe scraper is in active position, upon downward movement or the device in the well.

3. A device for taking samples from a well comprising a sample receiving chamber having an inlet, a wall scraper mounted relative to the chamber wall and movable to active or inactive positions, means arranged to be operated by fluid under pressure to move the scraper to active position to engage the wall of the well bole, said scraper being shaped to direct wall formation through said inlet into the chamber, when the scraper is-in active position, upon downward movement of the device in the well and sample entrapping means arranged to be brought into communication with said chamber for receiving and entrapping the sample for removal to the the wall of the well bore and to remove a portion of the formation therefrom upon longitudinal movement of the device in the well. of

5. A device for taking samples from a well comprising a body having a sample receiving chamber thereinprovided with an inlet, an out- .wardly movable member thereon, means arranged to' be actuated by fluidunder pressure to move said member outwardly into position to enbe'r outwardly, said outwardly movable member 7. A device for taking samples from a well "comprising a body having a sample receiving chamber therein provided with inlets and adapted to be connected to a'tubular operating string, a'

- fluid under pressure exerted through said string to move said expander in position to expand said outwardly movable members into position to engage the wall of the well bore and to remove a portion of the formation therefrom upon downward movement of thedevice in the well, said outwardly movable members being shaped to direct the removed formation through said inlets into said chamber on such movement of the device in the well. l 8. A device for taking samples from a we comprising a body having a sample receiving chamber therein provided with an inlet and adapted to be connected to a tubular operating string, an outwardly movable. member on the body, means for actuating said member outwardly into position-to engage the wall of the well bore and-to remove a portion or the formation therefrom upon downward movement of the device in the well, means arranged to be actuated by fluid pressure exerted through said member outwardly. said outwardly movable member being shaped to direct the removed formation through said inlet into said chamber'upon such movement of the device in the well and sample entrapping means to the ground surface.

shaped to be lowered into and. withdrawn from thecperating string and eflective to; receive and 'entrap the sample from said chamber for removal WALTER L. cnmtcn. 

